1. Field of the Invention
The present invention relates to a mobile communication terminal, and more particularly to an external antenna of a mobile communication terminal for providing a user with a multimedia broadcasting service.
2. Description of the Related Art
Generally, mobile communication terminals have call-receiving and call-transmitting functions. Recently, as portability and convenience of use of mobile communication terminals has improved, mobile communication terminals have been equipped with various functions for receiving entertainment services in addition to providing an original communication function. Such an entertainment service available for the mobile communication terminals is a multimedia public broadcasting service. In order to provide a user with such multimedia public broadcasting service, a mobile communication terminal must be equipped with a multimedia display function and an antenna capable of receiving signals of the multimedia public broadcasting service.
As generally known in the art, multimedia public broadcasting services are provided with a frequency band of 54 MHz to 805 MHz. For a satellite Digital Multimedia Broadcasting (DMB) service, a high frequency band of 2605 MHz to 2655 MHz is used. In addition, a frequency band used in personal mobile communication is about 830 MHz to 890 MHz or 1750 MHz to 1870 MHz. That is, the frequency band used for multimedia public broadcasting services is lower than the frequency band used for personal mobile communication. Since the frequency band of multimedia public broadcasting services is low, a wavelength of a signal of multimedia public broadcasting services is long. Accordingly, in order to receive the multimedia public broadcasting service signal, the antenna of the mobile communication terminal must be longer. For this reason, an antenna for receiving the signal of the multimedia public broadcasting service has to be of a length that is relatively longer than the length of an antenna for a general mobile communication terminal. Thus, if the antenna for receiving the multimedia public broadcasting service is accommodated in the mobile communication terminal, the size of the mobile communication terminal must be enlarged, and it becomes inconvenient to carry the mobile communication terminal.
Mobile communication terminals can receive satellite DMB signals through a general call receiving/transmitting antenna if the satellite DMB signals are indirectly transmitted to the mobile communication terminal by way of a transponder. In this case, however, signal sensitivity of the satellite DMB signals may be weakened and the satellite DMB signals cannot be transmitted to the mobile communication terminal in an area where the transponder is not installed. In addition, even if the mobile communication terminal adopts a frequency band similar to the frequency band of the satellite DMB service, which is higher than a frequency band applied to a conventional communication method, an antenna of the mobile communication terminal should be oriented in a direction of the satellite in order to obtain a high gain. Thus, it is advantageous to install the antenna at an external portion of the mobile communication terminal in order to obtain high performance from the mobile communication terminal.
Therefore, it is necessary to provide an antenna for receiving multimedia public broadcasting services and/or satellite broadcasting services by covering a wide range of frequency bands, greater than frequency bands covered by a conventional antenna of a mobile communication terminal.